Usopp and Kaya are close friends who have known each other since childhood. Both of them resided on Syrup Village, with Kaya living in the biggest mansion on the island. The two became good friends after Kaya lost both her parents and Usopp, with his talent for fabricating stories, would cheer her up with one of his tall tales which always made her smile. They have a great fondness of each other and, after the events with Kuro, have still kept each other in their thoughts since Usopp joined the Straw Hat Pirates.Shortly after her parents' deaths, Kaya developed an illness that risked taking her life as a result of the shock of losing them. With Usopp's father having joined the Red Haired Pirates when he was a child, and the untimely death of his own mother, he found great understanding in Kaya's grief and wished to make her days better. As a result, he would sneak onto the mansion grounds to climb into a tree outside her bedroom window where the two would chat all day, with Usopp telling grandiose tales about his adventures. He did all this despite the constant animosity he received from her personal butler, Klahadore. Whilst Kaya was fully aware that his stories were simply lies, she still enjoyed his company and would look forward to him coming to see her. She credits Usopp with helping her cope with her grief and ultimately recover from her illness.Their relationship is thrown into disarray, briefly, after Klahadore reveals to Usopp that he is a pirate by the name of Kuro, who had masterminded a scheme to steal Kaya's inheritance from her parents. Usopp desperately tries to inform Kaya of this but she does not believe him, believing he is telling a typical lie, but with the malicious goal of slandering Klahadore, and slaps him, ending their friendship. This leads to a stand off between Usopp, his new friends, Luffy, Nami and Zoro, and Kuro's entire pirate crew. In the process, Kaya discovers Klahadore's true identity and intentions, vindicating Usopp. Luffy is able to successfully defeat Kuro whilst Usopp protects Kaya from Kuro's subordinate, Jango.
